In the construction of small powered vehicles for all-terrain use, there are a number of design constraints to achieving a practical configuration which offers sufficient comfort and the ability to cope with difficult terrain. In particular, there is the need to achieve at least one steerable wheel with a shock-absorbing suspension system that is light in weight and which does not occupy too much of the volume of the vehicle needed for the occupant or occupants.
While one solution to the problem might be to use small-diameter wheels, this would render the vehicle less capable of climbing obstacles when used on surfaces that are not flat, level and uninterrupted. The use of larger-diameter wheels, for example greater than approximately 350 mm diameter, creates difficulties in designing a suspension system that will allow sufficient vertical travel while allowing for rotation about an axis for steering without the mechanical geometry intruding significantly into the user space.